More 28 is the fact that they can be viewed only from the air.
答案：(A) amazing
amazing（令人驚奇的）符合「這些線條只能從空中被看見」這件事令人驚訝的語意；hesitating／interacting／satisfying 均不符合此處語境。
四個選項都是 -ing 結尾的形容詞，形態一樣，你會憑中文挑一個。
鑑別度高達 64。線索一定要跨句才看得到。前面幾句一路在講納斯卡線有多驚人——巨大的圖形、複雜的圖案、幾千條筆直的線、占地五百平方公里、最長兩百七十五公尺、一千年前就畫好了。空格這一句 More ______ is the fact that they can be viewed only from the air（更______的是，這些線條只能從空中看見）用的是 More ＋ 形容詞的比較級，拿來跟前面那一整串比。既然前面講的都是驚人的事，這一句要再往上加一層，形容詞就必須是 amazing（令人驚奇的）。填進去讀成 More amazing is the fact that they can be viewed only from the air。順帶留意這個句型：More amazing is the fact that... 是把補語提到句首的倒裝，正常語序是 The fact that they can be viewed only from the air is more amazing。
hesitating（猶豫的）與 interacting（互動的）都只用在人或會互動的東西身上，一個事實不會猶豫，也不會互動；satisfying（令人滿意的）雖然是正面的，但這一句要講的是驚奇，不是滿意。三個都是 -ing 形容詞，形態吻合，容易被順手選走。
amazing（令人驚奇的）與 amazed（感到驚奇的）、More ＋ 形容詞 ＋ is the fact that ...（更……的是……，補語提前的倒裝）、the fact that ＋ 子句（……這個事實）、be viewed from the air（從空中看）、satisfying（令人滿意的）、perfectly straight（筆直的）。
In the desert of southwest Peru, enormous shapes, complex patterns, and thousands of perfectly straight lines are cut into the desert's surface. They are known as the Nazca lines and they 26 500 square kilometers. There are about fifty animal figures 27 275 meters long, including a monkey, a spider, and an "owl man." The last of these lines were drawn about 1,000 years ago.
More 28 is the fact that they can be viewed only from the air. Some people believe the Nazca Indians were 29 able to fly, perhaps in balloons. Others say the lines were landing areas for alien spaceships.
Maybe the lines were to carry water for farming, or were used as a calendar. The only thing certain is that the Nazca lines remain one of the world's most fascinating 30 mysteries.